DESCRIPTION (Investigator's Abstract): The purpose of this research is to do exploratory research on the isolation, biological testing, and identification of potentially useful natural products from Monteverde, Costa Rica. Specifically, the investigators will collect plan materials from the Monteverde Cloud Forest Reserve and the Monteverde community, Costa Rica. The investigators will concentrate the investigators screening on the Araliaceae, Euphorbiaceae, Clusiaceae, Proteaceae, and Acanthaceae families. Crude extracts from these plants will be tested for fungicidal and bacteriocidal activity, antiviral activity, and cytotoxicity. Those extracts which show biological activity will be fractionated and the active compounds identified. Preliminary studies of crude extracts indicate six members of Arliaceae show remarkable in vitro cytotoxic activity against human Hep G2 hepatocellular carcinoma cells but limited cytotoxic activity against normal adult rat hepatocytes. Chloroform extracts from three species of Oreopanax were active against the yeast, Saccharomyces cerevisiae. In addition, two of the species exhibited antifungal activity against Aspergillus niger. Essential oil from Guettardo poasana shows antifungal activity against Candida albicans and S. cerevisiae. Essential oil from Zanthoxylum melanostichum shows activity against C. albicans, S. cerevisiae, as well as A. niger. Root extracts from two species of Clusia show antibacterial activity against the gram-positive bacteria Bacillus cereus and Staphylococcus aureus. This project is especially attractive in that not only would it provide additional new pharmacopeia from natural sources (before those sources are lost through deforestation and other habitat destruction), but it would also serve to provide additional arguments for conserving the diversity of the tropics as well as identifying potential alternative (and ecologically less damaging) "cash crops" for critical tropical habitats. Thus, this project also addresses the problem of the degenerating environment in tropical America; the crisis of the decline of biodiversity in these areas. Specifically, this project will involve:(a) an inventory of tropical biota in terms of medicinal natural products; (b) conservation of tropical natural areas; and (c) identifying alternative cash crops for critical tropical habitats. Another attractive feature of this project is the interdisciplinary nature of the research. There are four principal collaborators who bring many different areas of complementary expertise into the project. In addition, the project provides hands-on experience for undergraduate students. The Departments of Chemistry and Biological Sciences and the University of Alabama in Huntsville are all acutely aware of the potential shortage of future scientists and the investigators are therefore committed to undergraduate research participation as part of quality scientific education and training.